Piston-packing.



PERCY EARL WILLIAMS, OF SAVANNAH, GEORGIA.

PISTON-PACKING.

Specification of Letters Patent.

Patented July 21, 190s.

Application led November 2, 1907. Serial No. 400,404.

To all whom it may concern:

Be it known that I, PERCY EARL WIL- LIAMS, a citizen of the UnitedStates, residing at Savannah, Chatham county, Georgia, have inventedcertain new and useful Improvements in Piston-Packings; and I do herebydeclare the following to be a full, clear, and exact description of theinvention, such as will enable others skilled in the art to which itappertains to make and use the same.

This invention relates to certain improvements in iston packings, andrelates more particular y to improvements in expanding devices for thecupped washers of pump pistons and the like; and the objects and natureof my invention will be readily understood by those skilled in the artin the light of the construction shown in the accompanying drawings asmy preferred embodiment from among other arrangements within the spiritand scope of my invention.

An obj ect of the invention is to provide an exceedingly simple, durableand inexpensive device for expanding the cupped washers of pistons forpumps or the like, whereby the working efficiency of such pistons willbe increased.

The invention consists in certain novel features in construction and incombinations and arrangements of parts as more fully and particularlyset forth hereinafter.

Iteferring to the accompanying drawings Figure l, is a longitudinalsectional view through my improved piston packing,

showing a portion of the cylinder in which the piston works. Fig. 2, isan end elevation of the piston. Fig. 3, is a detail detached perspectiveview showing the parts of the piston separated, excepting the cupped 1washer.

In the drawings, l, is a cylinder such as that of an air compressor, airor water pump or any other cylinder adapted to receive a reciprocatingpiston having a cupped packto permit the passage of water or gas betweenthe same and the inner surface of the piston.

5, is the stii backing or head of the piston which in the specificexample illustrated, is in the form of a round flat metal disk securedagainst the end of the piston rod and fitting against the outer flatface of the packing washer or gasket 3.

The packing washer and the piston head, in the specific exampleillustrated, are removably secured to the piston rod by a headed machinescrew 6, passed inwardly through a central perforation in a spiderframe, hub 7, arranged at the inner face of the packing washer, andthrough the packing Washer and piston head into a screw threaded holelongitudinally into the end of the piston rod. The screw passesremovably through the various elements named and clamps them togetherremovably, whereby the parts can be readily separated for repair orreplacement. However, I do not wish to limit my invention to thespecific construction described for securing the parts together as otherdevices and arrangements might be employed for this purpose.

The spider frame can be formed in one piece of metal of the requiredstrength and stiffness and can be if found desirable cut or pressed fromsheet metal. rIhis spider frame consists of the circumferential ring 8connected to the central portion of hub 7 by several spaced radial arms.The ring S is concentrically arranged within the piston and in diameteris preferably less than the diameter of the piston head 5, and than theinternal diameter of the cupped edge of the packing washer. The ring 8,is spaced a distance inwardly from the normal flat position of thepacking washer by any suitable means or arrangement. As a simple andeffective means for this purpose, I show the spider dished with its hub7, pressed inwardly beyond the plane of the ring 8. The hub 7, restsagainst the face of the washer and the radial arms incline inwardlytherefrom to the ring, whereby the ring 8, is held spaced the requireddistance from the flat face of the washer while the hub is clampedagainst the same by the screw 6. An annular coiled expanding spring 10,is throughout its length coiled loosely around the ring 8, so that thespring completely surrounds and incloses the ring. The diameter of theconvolutions of this coiled Wire spring l0, is

greater than the width and thickness of the ring 8, in cross section sothat the spring is free to expand and contract on the ring to the extentof the diameter of its convolutions. The spring is arranged within thecupped edge of the Washer and against the front face of the flat portionthereof, and in fact lies entirely within the washer and its cupped edgeand constantly tends to press the saine outwardly against the innersurface of the cylinder with a uniform light outward pressure throughoutthe circumference of the cupped edge, thereby taking up the wear of thewasher and maintaining the desired tight rubbing contact thereof withthe cylinder surface. The spring is held in proper position by the ringwhich also limits its movements within the necessary bounds. The springis sufficiently light or of such strength to permit the desired slightflexing or contraction of the packing washer on the outward movement ofthe piston to permit the passage of gas or liquid between the cuppedportion of the packing washer and the cylinder surface.

rIhe device described is durable in construction and is composed of asmall number of inexpensive parts and by employing the spring in therelation described, the efficiency of cupped washer pistons is greatlyenhanced, and at the same time, in case of wear or breakage, the worn orbroken spring can be easily removed and a new and proper spring insertedon the ring of the spider.

What I claim and desire to secure by Letters Patent of the United Statesis l. A piston having a cupped packing Washer, an annular expansivecoiled spring lying against the inner face of the washer and within andexpanding the cupped edge thereof, and supporting means for said spring.

2. An expanding device for cupped piston packing washers consisting ofan annular expansive coiled spring, and a ring loosely encircled therebyand arranged therein.

3. A piston having a cupped packing washer, an expansive annular coiledspring fitted Within and expanding said washer around the inner surfaceof the cupped edge thereof, and means loosely confining said springagainst the flat inner face of the Washer.

4. A piston having a cupped packing washer, and an annular coiledexpanding spring resting against the inner face of the washer and'fitting within the cupped edge thereof and expanding the same.

5. A piston having a cupped packing wash r, a ring arranged withinthe'c'pped et ge thereof and provided with securing means, and a looseannularl coiled expanding spring encircling said ring loosely and fittedwithin and expanding the cupped edge of said washer.

6. A piston having an annular' flexible packing, and a dished spidercarrying a loose annular coiled spring, within said packing andexpanding the saine.

7. A piston having expansible packing means, in combination with anannular coiled expansible spring lying within and expanding said means,and supporting stop means carried by the piston and permitting freemovement of said spring within certain limits and confining the saineloosely in position within said packing means.

8. A piston having expansible packing means, in combination with a looseannular coiled expanding spring arranged within said packing andexpanding the same, and a support for said spring arranged within theconvolutions thereof.

9. A piston having a cupped aeking washer, and a loosely mounted free ymovable annular coiled spring resting loosely against the rear face ofthe body portion of the washer and within and expanding the cupped edgeof said washer.

10. A piston having a flexible packing washer at its central portionsecured to the central portion of the piston and loosely facing the rearthereof and having a rear wardly extending annular flexible cupped edge,in combination with loosely confined and freely movable expanding meansresting against the rear face of the central portion of said washer andwithin and expanding said cupped edge.

In testimony whereof I affix my signature, in presence of two witnesses.

PERCY EARL WILLIAMS.

I/Vitnesses:

F. M. OLIVER, JAMES F. EVANS.

